7.3.6 PDCP Others

36.523-13GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 1: Protocol conformance specificationRelease 17TSUser Equipment (UE) conformance specification

7.3.6.1 PDCP Discard

7.3.6.1.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { the Discard Timer for a PDCP SDU expires }

then { UE discards the corresponding PDCP SDU }

}

7.3.6.1.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: 3GPP TS 36.323 clause 5.9.

[TS 36.323, clause 5.4]

When the Discard_Timer expires for a PDCP SDU, or the successful delivery of a PDCP SDU is confirmed by PDCP status report, the UE shall discard the PDCP SDU along with the corresponding PDCP PDU. If the corresponding PDCP PDU has already been submitted to lower layers the discard is indicated to lower layers.

7.3.6.1.3 Test description

7.3.6.1.3.1 Pre-test conditions

System Simulator:

– Cell 1

UE:

None.

Preamble

– The UE is in state Loopback Activated (state 4) according to [18 with the exceptions listed in table 7.3.6.1.3.1-1 applicable for the configured UM DRB and table 7.3.6.1.3.1-2 for SR configuration.

– The condition SRB2-DRB(1,1) is used for step 8 in 4.5.3A.3 according to [18].

Table 7.3.6.1.3.1-1: PDCP Settings

Parameter

Value

Discard_Timer

500 ms

Table 7.3.6.1.3.1-2: SchedulingRequest-Config (preamble Table 4.5.3.3-1: Step8)

Derivation Path: 36.508 Table 4.6.3-20

Information Element

Value/remark

Comment

Condition

dsr-TransMax

n64

7.3.6.1.3.2 Test procedure sequence

Table 7.3.6.1.3.2-1: Main behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

–

EXCEPTION: The SS should not allocate UL grants unless when explicitly stated so in the procedure.

–

–

–

–

1

The SS creates 5 PDCP Data PDUs and the Next_PDCP_TX_SN is set to "0".

–

–

–

2

Void

–

EXCEPTION: Step 3 shall be repeated for k=0 to 2 (increment=1) with the below specified PDU size sent to the UE:

Data PDU#1 = 46 bytes for k=0

Data PDU#2 = 62 bytes for k=1

Data PDU#3 = 78 bytes for k=2

–

–

–

–

3

The SS sends a PDCP Data PDU via RLC-UM RB with the following content to the UE:

D/C field = 1 (PDCP Data PDU) and PDCP SN = k

After having sent a PDU, the SS sets Next_PDCP_TX_SN = k+1.

<–

PDCP DATA PDU (SN=k)

4

Wait for Discard_Timer to expire.

Note: According to TS36.508, timer tolerance should be 10% of Discard_Timer or 5 x RTT, whichever is greater. RTT = 8 TTIs for FDD and RTT = 16 TTIs for TDD

–

–

–

–

–

EXCEPTION: Step 5 shall be repeated for k=3 to 4 (increment=1) with the below specified PDU size sent to the UE:

Data PDU#4 = 94 bytes for k=3

Data PDU#5 = 110 bytes for k=4

–

–

–

–

5

The SS sends a PDCP Data PDU via RLC-UM RB with the following content to the UE:

D/C field = 1 (PDCP Data PDU) and PDCP SN = k

After having sent a PDU, the SS set Next_PDCP_TX_SN = k+1.

<–

PDCP DATA PDU (SN=k)

–

–

6

The SS resumes normal UL grant allocation.

–

–

–

–

7

Check: Does UE transmit a PDCP Data PDU # 4 of size 94 bytes? (Note1)

–>

PDCP Data PDU # 4

1

P

8

Check: Does UE transmit a PDCP Data PDU # 5 of size 110 bytes ? (Note1)

–>

PDCP Data PDU # 5

1

P

Note1: PDCP Data PDU contents are checked to verify that the UL PDU is same as the DL PDU. According to the note in TS 36.323 [38] clause 5.1.1 in case of PDCP SDUs being dicarded it is up to UE implementation which SN to be used and therefore the SN cannot be checked.

7.3.6.1.3.3 Specific message contents

None.

7.3.6.2 Ethernet header compression and decompression / Correct functionality of ethernet header compression and decompression

Editor’s note: Configuration of ethernet protocol is FFS.

7.3.6.2.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {
when { Ethernet header compression functionality is taken into use }

then { UE performs correct ethernet header compression and decompression. }

}

7.3.6.2.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.323, clause 5.14.

[TS 36.323, clause 5.14.2]

PDCP entities associated with DRBs can be configured by upper layers TS 36.331 [3] to use EHC. Each PDCP entity carrying user plane data may be configured to use EHC. Every PDCP entity uses at most one EHC compressor instance and at most one EHC decompressor instance.

[TS 36.323, clause 5.14.3]

The usage and definition of the parameters shall be as specified below.

– MAX_CID_EHC_UL: This is the maximum CID value that can be used for UL. One CID value shall always be reserved for uncompressed flows. The parameter MAX_CID_EHC_UL is configured by upper layers (maxCID-EHC-UL in TS 36.331 [3]);

[TS 36.323, clause 5.14.4]

If EHC is configured, the EHC protocol generates two types of output packets:

– EHC compressed packets (i.e. EHC full header packets and EHC compressed header packets), each associated with one PDCP SDU;

– standalone packets not associated with a PDCP SDU, i.e. EHC feedback packets.

An EHC compressed packet is associated with the same PDCP SN and COUNT value as the related PDCP SDU.

EHC feedback packets are not associated with a PDCP SDU. They are not associated with a PDCP SN and are not ciphered.

[TS 36.323, clause 5.14.5]

If EHC is configured by upper layers for PDCP entities associated with user plane data, the PDCP Data PDUs are decompressed by the EHC protocol after performing deciphering as explained in clause 5.6.

[TS 36.323, clause 5.14.6.1]

When an EHC feedback packet is generated by the EHC protocol, the transmitting PDCP entity shall:

– submit to lower layers the corresponding PDCP Control PDU as specified in clause 6.2.18, i.e., without associating a PDCP SN, nor performing ciphering.

[TS 36.323, clause 5.14.6.2]

At reception of a PDCP Control PDU for EHC feedback packet from lower layers, the receiving PDCP entity shall:

– deliver the corresponding EHC feedback packet to the EHC protocol without performing deciphering.

7.3.6.2.3 Test description

7.3.6.2.3.1 Pre-test conditions

System Simulator:

– Cell 1.

UE:

– None.

Preamble:

– The UE is in state Loopback Activated (State 4) with one DRB established in UM mode according to [18].

7.3.6.2.3.2 Test procedure sequence

Table 7.3.6.2.3.2-1: Main Behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The SS reconfigures data radio bearer with RRCConnectionReconfiguration message containing the configuration of data radio bearer in the drb-ToAddModify with PDCP-Config to enable ethernet Header Compression functionality.

<–

RRCConnectionReconfiguration

–

–

2

UE transmits a RRCConnectionReconfigurationComplete message to confirm the reconfiguration of data radio bearer with ethernet header compression functionality enabled.

–>

RRCConnectionReconfigurationComplete

–

–

3

SS transmits a ciphered PDCP Data PDU with unique Context ID containing full header ethernet packet.

<–

PDCP Data PDU #0

–

–

4

CHECK: Does UE transmit unciphered EHC feedback packet with Context ID set in step 3?

–>

PDCP Control PDU #0

1

P

5

CHECK: Does UE transmit ciphered looped back PDCP Data PDU with unique Context ID containing full header ethernet packet?

–>

PDCP Data PDU #0

1

P

6

SS transmits unciphered EHC feedback packet with Context ID set in step 5

<–

PDCP Control PDU #0

7

SS transmits a ciphered PDCP Data PDU with unique Context ID set in step 3 containing compressed header ethernet packet.

<–

PDCP Data PDU #1

–

–

8

CHECK: Does UE transmit ciphered looped back PDCP Data PDU with Context ID set in step 5 containing compressed header ethernet packet?

–>

PDCP Data PDU #1

1

P

7.3.6.2.3.3 Specific message contents

Table 7.3.6.2.3.3-1: RRCConnectionReconfiguration (step 1, Table 7.3.6.2.3.2-1)

Derivation Path: 36.508 clause 4.6.1

RRCConnectionReconfiguration ::= SEQUENCE {

criticalExtensions CHOICE {

c1 CHOICE{

radioResourceConfigDedicated

RadioResourceConfigDedicated-DRB-Mod-EHC

}

}

}

Table 7.3.6.2.3.3-2: RadioResourceConfigDedicated-DRB-Mod-EHC (Table 7.3.6.2.3.3-1)

Derivation Path: 36.508 clause 4.6.3, table 4.6.3-27 RadioResourceConfigDedicated-DRB-Mod

Information Element

Value/remark

Comment

Condition

RadioResourceConfigDedicated-DRB-Mod ::= SEQUENCE {

drb-ToAddModList

DRB-ToAddModList-EHC

}

}

Table 7.3.6.2.3.3-3: DRB-ToAddModList-EHC (Table 7.3.6.2.3.3-2)

Derivation Path: 36.331 clause 6.3.2

Information Element

Value/remark

Comment

Condition

DRB-ToAddModList ::= SEQUENCE (SIZE (1..maxDRB)) OF SEQUENCE {

1 Entries

eps-BearerIdentity[1]

Not present

drb-Identity[1]

1

pdcp-Config[1]

PDCP-Config-EHC

rlc-Config[1]

Not present

logicalChannelIdentity[1]

Not present

logicalChannelConfig[1]

Not present

}

Table 7.3.6.2.3.3-4: PDCP-Config-EHC (Table 7.3.6.2.3.3-3)

Derivation Path: 36.331 clause 6.3.2

Information Element

Value/remark

Comment

Condition

PDCP-Config ::= SEQUENCE {

ethernetHeaderCompression-r16 SEQUENCE {

ehc-Common-r16 SEQUENCE {

ehc-CID-Length-r16

bits15

}

ehc-Downlink-r16 SEQUENCE {

drb-ContinueEHC-DL-r16

true

}

ehc-Uplink-r16 SEQUENCE {

maxCID-EHC-UL-r16

32767

drb-ContinueEHC-UL-r16

true

}

}

}